Tang Tao, Bai Jinhai, Ao Zhipeng, Wei Zehong, Hu Yi, Liu Shaojun
State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Sciences, Hunan Normal University, Changsha 410081, China.
Hunan Engineering Research Center for Utilization of Characteristics of Aquatic Resources, Hunan Agricultural University, Changsha 410128, China.
Animals (Basel). 2021 Jun 2;11(6):1655. doi: 10.3390/ani11061655.
The present study investigated the effects of dietary paper mulberry (, BP) on growth performance, muscle quality and muscle growth-related mRNA expressions of grass carp. Fish (initial weight: 50.0 ± 0.5 g) were fed diets supplemented with 0% (control diet), 5%, 10%, 15% and 20% BP for 8 weeks. The results showed that increasing levels of paper mulberry linearly and quadratically decreased the special gain rate (SGR) and increased the feed conversion rate (FCR) of grass carp ( 0.05). Significantly positive quadratic trends were found between paper mulberry levels and muscle crude fat or crude protein of grass carp ( 0.05). In comparison to the control diet, the 10%BP and 15%BP groups had significantly decreased muscle crude fat and increased crude protein ( 0.05). The levels of paper mulberry resulted in a linear and quadratic increase in water loss of grass carp muscle ( 0.05), and all groups with paper mulberry supplementation were significantly higher than the control group ( 0.05). Significant positive linear and quadratic trends were found between the paper mulberry levels and muscle fiber diameter or density of grass carp ( 0.05). In comparison to the control diet, the significant differences were found in the 15%BP and 20%BP groups ( 0.05). The muscle adhesiveness and hardness linearly and quadratically increased with the increasing levels of paper mulberry ( 0.05), and both of which increased significantly when the level of paper mulberry reached 10% ( 0.05). In addition, the increase in paper mulberry linearly and quadratically improved the expressions of myoblast determination protein (MyoD), myogenin (MyoG), paired box protein 7 (Pax7) and myostatin 1 (MSTN1) ( 0.05). When the supplementation of paper mulberry reached 15%, the expressions of all these mRNAs were significantly higher than those of the control group ( 0.05). In summary, adding 5% paper mulberry did not affect the growth of grass carp. However, the supplementation of 10% paper mulberry could improve muscle quality through improving muscle hardness, reducing fat accumulation and muscle fiber diameter, at the cost of reducing growth performance.
本研究调查了饲料中添加构树（BP）对草鱼生长性能、肌肉品质及肌肉生长相关mRNA表达的影响。将初始体重为50.0±0.5克的草鱼投喂添加0%（对照饲料）、5%、10%、15%和20%构树的饲料，为期8周。结果表明，构树添加水平的增加呈线性和二次曲线降低草鱼的特定生长率（SGR），并提高其饲料转化率（FCR）（P<0.05）。构树水平与草鱼肌肉粗脂肪或粗蛋白之间呈显著的正二次曲线趋势（P<0.05）。与对照饲料相比，10%BP和15%BP组肌肉粗脂肪显著降低，粗蛋白增加（P<0.05）。构树水平导致草鱼肌肉失水呈线性和二次曲线增加（P<0.05），所有添加构树的组均显著高于对照组（P<0.05）。构树水平与草鱼肌纤维直径或密度之间呈显著的正线性和二次曲线趋势（P<0.05）。与对照饲料相比，15%BP和20%BP组存在显著差异（P<0.05）。肌肉黏附性和硬度随构树水平的增加呈线性和二次曲线增加（P<0.05），当构树水平达到10%时，二者均显著增加（P<0.05）。此外，构树添加量的增加呈线性和二次曲线提高成肌决定蛋白（MyoD）、肌细胞生成素（MyoG）、配对盒蛋白7（Pax7）和肌肉生长抑制素1（MSTN1）的表达（P<0.05）。当构树添加量达到15%时，所有这些mRNA的表达均显著高于对照组（P<0.05）。综上所述，添加5%构树不影响草鱼生长。然而，添加10%构树可通过提高肌肉硬度、减少脂肪积累和肌纤维直径来改善肌肉品质，但代价是生长性能降低。
